This invention relates to the field of thin-film deposition and, more particularly, to improvements in sputtering processes for depositing thin-films on a workpiece or substrate.
In the published Japanese Patent Application 59-93878 by H. Yamamoto, there is disclosed a sputtering system which makes use of a substantially enclosed sputtering target which serves to contain a sputtering plasma during the sputtering process and thereby prevent the plasma from interfering with the sputtered film formation. The target itself is made of a single element (viz., tungsten or niobium), and it is mentioned that the target could be made in such a manner as to avoid the emergence of high energy electrons from the target. Such electrons are to be avoided because they often act to increase the temperature of the film-receiving substrate to an intolerably high level. But there is no disclosure in this reference of how the particular targets disclosed could be modified to achieve the goal of suppressing these secondary electrons.